Growing evidence supports that air pollution exposure has become a risk factor of type II diabetes mellitus through the induction of insulin resistance (IR), but the presented findings did not provide a consistent relationship between air pollution exposure and IR in the temporal scale and the magnitude. Reported associated with IR and air pollution exposure, branched-chain amino acids (BCAAs) in blood might modify the association between air pollution exposure and IR. We took advantage of an existing panel study on elderly people who were healthy or with pre-diabetes. Amino acids were analyzed from the serum samples using a UPLC-QQQ-MS, and the homeostasis model assessment of insulin resistance (HOMA-IR) values were calculated to represent the levels of IR in each visit. Exposures to PM_2.5, NO₂, SO₂, CO, O₃, and black carbon (BC) were estimated using data from a monitoring station. Linear mixed-effects models were applied to estimate the associations between the air pollution and HOMA-IR, as well as the modifying effects of BCAAs. We found significantly higher concentrations of BCAAs in the pre-diabetic subjects than healthy ones. The concentrations of BCAAs were all significantly associated with HOMA-IR. For subjects with high-level BCAAs, HOMA-IR was positively associated with an IQR increase in PM_2.5, NO₂, BC, and CO at lag day 2 and in PM_2.5, SO₂, NO₂, BC, and CO at lag day 7. While for subjects with low-level BCAAs, there was no significant association observed at any lag day except for CO at lag day 5. The study provided evidence that circulating BCAAs may modify the relationship between air pollution exposure and the level of insulin resistance in humans.

越来越多的证据支持空气污染暴露已通过诱导胰岛素抵抗 (IR) 成为 II 型糖尿病的危险因素，但目前的研究结果并未提供空气污染暴露与 IR 在时间尺度和幅度上的一致关系. 据报道，血液中的支链氨基酸 (BCAA) 与 IR 和空气污染暴露有关，可能会改变空气污染暴露与 IR 之间的关联。我们利用了现有的针对健康或糖尿病前期的老年人的小组研究。使用 UPLC-QQQ-MS 从血清样品中分析氨基酸，并计算胰岛素抵抗的稳态模型评估 (HOMA-IR) 值以代表每次访问中的 IR 水平。暴露于 PM _2.5 , NO ₂、SO ₂、CO、O ₃和黑碳 (BC) 是使用来自监测站的数据估算的。应用线性混合效应模型来估计空气污染与 HOMA-IR 之间的关联，以及 BCAA 的修正效应。我们发现糖尿病前期受试者的支链氨基酸浓度明显高于健康受试者。BCAAs 的浓度都与 HOMA-IR 显着相关。对于具有高水平 BCAA 的受试者，HOMA-IR 与延迟第 2 天PM _2.5、NO ₂、BC 和 CO 以及 PM _2.5、SO ₂、NO ₂的 IQR 增加呈正相关、BC 和 CO 在滞后第 7 天。而对于具有低水平 BCAA 的受试者，除了滞后第 5 天的 CO 外，在任何滞后日均未观察到显着关联。该研究提供的证据表明循环 BCAA 可能会改变空气之间的关系污染暴露和人类胰岛素抵抗水平。